The present invention relates to a process for positioning the liquid medium in a liquid medium cell and to a corresponding cell. It is used in optoelectronics and particularly in the production of a screen for displaying pictures and/or alphanumeric data.
Such a cell comprises a liquid medium placed between two flat walls, which are generally thin compared with their transverse dimensions and which are generally made from glass, whilst being kept spaced from one another. The two walls are joined to one another in the vicinity of their edges by means of resins or other appropriate binders making it possible to lock them in the correct position. The two walls can be kept at a particular spacing from one another e.g. by means of shims, which are in particular arranged along the welded edges or are distributed as uniformly as possible between the two walls. It can also be obtained by using rigid walls, e.g. as a result of their relatively great thickness.
In the display field, the most commonly used liquid medium is a liquid crystal which, as its name indicates, has in the liquid state properties characteristic of solid crystals and in particular with regards to the anisotropy.
In general, to obtain a satisfactory operation of the cell, its entire useful area must be filled with liquid medium. However, it is known that during the filling of the cell with liquid medium, gas bubbles appear within the cell. These gas bubbles must be positioned at a point within the cell, which is not liable to prejudice the operation thereof. Thus, the presence of gas bubbles in the useful area of the cell can be particularly prejudicial, when the cell ia used in the display of images and/or alphanumeric data.